Battle of Tannenberg

The Battle of Tannenberg was fought from 26 to 30 August 1914 at the start of the Eastern Front of World War I. The battle occurred amid a Russian offensive into German East Prussia, and it resulted in the destruction of the Russian 2nd Army and the Germans' vengeance for their defeat at nearby Grunwald in 1410.

Background
At the start of the war, Germany intended to stand on the defensive against Russia until France had been defeated in the west. Germany assumed Russian mobilization would take at least 40 days to complete. The Russians, however, had promised the French that Russian forces would launch an attack against Germany within 15 days of the outbreak of war. Russia planned to begin its role in the war by taking the offensive against Austria-Hungary.

Battle
Following the dictates of the Schlieffen Plan, the Germans had sent seven of their eight armies to Belgium and France. The German 8th Army, commanded by General Maximilian Prittwitz, was to act as a holding force until troops could be transferred from the west. The Russians, their forces divided between the German and Austro-Hungarian fronts, had two armies available for an invasion of East Prussia, giving them considerable local superiority in manpower. Honoring their agreement with France, the Russians attacked on day 15 of the war, even though their mobilization was far from complete.

The advance of Russian troops onto German soil, preceded by marauding Cossack cavalry, sent a wave of panic through Germany. Roads were clogged with East Prussian refugees fleeing westward. Abandoning prepared defensive positions, the German 8th Army advanced toward the Russian 1st Army. Commanded by General Paul von Rennenkampf, the Russians repelled German attacks at Gumbinnen.

Role of intelligence
When reconnaissance aircraft reported the advance of the Russian 2nd Army to the south of the Masurian Lakes, Prittwitz panicked and ordered a general withdrawal to the Vistula, angering the German high command. Prittwitz was fired and replaced by veteran General Paul von Hindenburg, with General Ludendorff - the hero of the recent siege of Liege - as his Chief of Staff.

Hindenburg and Ludendorff arrived in East Prussia to find a perfectly viable plan for a counteroffensive already in place, devised by Prittwitz's staff. Gambling that the fighting at Gumbinnen would have temporarily halted Rennenmakpf, the Germans decided to concentrate their forces against the Russian 2nd Army, commanded by General Alexander Samsonov, which was blithely pushing forward almost unopposed through the forests to the south.

The German plan took advantage of aerial reconnaissance, by both primitive Taube airplanes and airships. An intercepted Russian radio message, transmitted uncoded, confirmed that Rennenkampf was not intending to resume his advance.

Setting the trap
Leaving a thin screen of cavalry and reserves in front of the Russian 1st Army, an entire German corps under General Hermann von Francois was moved by train to the south of the Russian 2nd Army. Other German troops marched fromGumbinnen toward Samsonov's northern flank. Samsonov was ignorant of the position of German forces and had no contact with the Russian 1st Army. Nonetheless, a spirit of optimism reigned. When German flank attacks began on 26-27 August, Samsonov pressed forward. By 29 August, the German pincers had closed behind him and most of the Second Army was trapped. Having lost control of his forces, Samsonov walked into the forest and shot himself. Claiming a great victory, the Germans named it Tannenberg after a 15th-century battle famed in Prussian history.

Aftermath
Germany was to find no easy victory on the Eastern Front to compensate for its failure to win in the west. The Russians recovered from Tannenberg. When the Germans turned their forces against the Russian 1st Army in September, Rennenkampf managed a fighting withdrawal at the First Battle of the Masurian Lakes and then mounted a successful counteroffensive. Russia was also scoring successes against the Austro-Hungarians in Galicia, and figting on the Eastern Front continued in Poland. Hindenburg and Ludendorff took the credit for saving Germany from the Russian hordes, and the two generals were endowed with almost magical prestige. Their rise to power had begun.